In urban environments, dogs are required to be leashed when they are outside their own home fence limits. Dogs usually wear a collar at all times. These collars carry the dog license and sometimes the dog's separate identification. The collar also has an eye thereon which can be engaged by a leash. Dogs are often taken for a walk while controlled by a leash.
The leash is carried in the walker's hands and is snapped to the eye in the dog's collar. Sometimes the dog is large and the dog walker is small. When a dog becomes excited, for example, chasing a squirrel, uncomfortable and sometimes damaging shock can be transferred through the leash to the dog walker. In order to protect the dog walker's arm against damage, a shock absorber which can be installed between the leash and the dog collar is desirable.